In lamp heating and curing of adhesives, sealants or coatings in industrial applications, one or more microwave generators, for example, magnetrons, are used to provide microwave radiation to a lamp source, such as an electrodeless ultraviolet (UV) lamp. When the plasma of the lamp is sufficiently excited by the microwave radiation from each magnetron, the lamp illuminates to provide the necessary light wavelength and intensity for the particular heating or curing process.
Microwave-excited lamp power supply systems often have one or more high voltage power supplies that provide higher voltages to one or more magnetrons and low voltage power supplies that provide a lower voltage to a blower, a magnetron filament and other devices. The power supply system is often electrically coupled to sensors positioned within the system and the lamp head. It has been observed that as a magnetron ages and approaches the end of its useful life, there is a higher probability of the magnetron experiencing short circuits that result in high voltage arcing. Further, on occasion, the high voltage circuit components associated with the magnetron can experience a short circuit. In either event, any such short circuits can cause components associated with the high voltage power supply to experience either a life shortening stress or destruction.
Therefore, there is a need to provide apparatus and methods of detecting short circuit conditions in an output circuit of a high voltage power supply driving a microwave generator and minimizing or eliminating any harmful effects and damage.